Publications associées à Dynamics and Optimal Control of Self-Sustained Instabilities in Laminar and Turbulent Swirling Flows: Application to the Part Load Vortex Rope in Francis Turbines

Boundary layer effects on the vortex shedding in a Donaldson-type hydrofoil

François Avellan, Mohamed Farhat, Amirreza Zobeiri, Eduard Egusquiza

Structure Interaction (FSI) phenomena is becoming a relevant study field for the design or revamping of hydropower plants. The generalized trend of increasing flow rates and reducing rotor blades/stay vanes thickness in order to improve the efficiency of t ...

International Association For Hydraulic Research2014

A linearized approach for the control of aerodynamic forces in flow past a square cylinder

François Gallaire, Edouard Boujo, Philippe Meliga

The analysis of Strykowski & Sreenivasan (JFM, 1990) provides experimental evidence that a small control cylinder suitably positioned in the wake of a main cylinder can alter vortex shedding close to the instability threshold. This problem was addressed fr ...

2014

Open-loop control of a separated boundary layer

François Gallaire, Edouard Boujo

Linear optimal gains

G_{opt}(\omega)

are computed for the separated boundary-layer flow past a two-dimensional bump in the subcritical regime. Very large values are found, making it possible for small-amplitude noise to be strongly amplified and to desta ...

Elsevier France-Editions Scientifiques Medicales Elsevier2014

Obstacle-induced spiral vortex breakdown

Mohamed Farhat, François Gallaire, Matthieu Dreyer, Simon Pasche

An experimental investigation on vortex breakdown dynamics is performed. An adverse pressure gradient is created along the axis of a wing-tip vortex by introducing a sphere downstream of an elliptical hydrofoil. The instrumentation involves high-speed visu ...

Springer2014

A 10-W modified LINC Power amplifier with a reduced-size Chireix Power Combiner

Adil Koukab

This paper reports a miniaturization technique of non-isolated power combiners and its application for a compact outphasing transmitter. The technique is used to build an LDMOS Z-LINC system. The maximum output power and PAE measured at 900 MHz are 9.3 W a ...

Ieee2014

Étude systémique pour l'alimentation hybride

Simon Delalay

Nowadays most of the decisions in the field of energy supply lead to an increased use of renewable energy resources. Such decisions imply several consequences for instance in electrical power generation. Indeed, replacing conventional energy sources by mor ...

EPFL2013

Efficient Computation of Sensitivity Coefficients of Node Voltages and Line Currents in Unbalanced Radial Electrical Distribution Networks

Jean-Yves Le Boudec, Mario Paolone, Dan-Cristian Tomozei, Konstantina Christakou

The problem of optimal control of power distribution systems is becoming increasingly compelling due to the progressive penetration of distributed energy resources in this specific layer of the electrical infrastructure. Distribution systems are, indeed, e ...

Ieee-Inst Electrical Electronics Engineers Inc2013

Open-loop control of a separated boundary layer

François Gallaire, Edouard Boujo

Linear optimal gains

G_opt(\omega)

are computed for the separated boundary-layer flow past a two-dimensional bump in the subcritical regime. Very large values are found, making it possible for small-amplitude noise to be strongly amplified and to destabi ...

Cépaduès Editions2013

Forced reattachment in separated flows: a variational approach to recirculation length reduction

François Gallaire, Edouard Boujo

Sensitivity analysis is used to design an open-loop control for separated flows. The length of the recirculation region

l_c

is expressed as a cost functional, and its sensitivity to actuation is derived analytically. This analysis allows to identify regi ...

2013

Study of optimal design of polygeneration systems in optimal control strategies

François Maréchal, Mario Paolone, Ramanunni Parakkal Menon

The concept of smart grids being developed involves interdependence between the electrical, thermal and material flows. Control strategies are required for the optimal operation of these modern grids. This paper studies the optimal design of multi-node mic ...

Elsevier2013

Dynamics and Optimal Control of Self-Sustained Instabilities in Laminar and Turbulent Swirling Flows: Application to the Part Load Vortex Rope in Francis Turbines

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Boundary layer effects on the vortex shedding in a Donaldson-type hydrofoil

A linearized approach for the control of aerodynamic forces in flow past a square cylinder

Open-loop control of a separated boundary layer

Obstacle-induced spiral vortex breakdown

A 10-W modified LINC Power amplifier with a reduced-size Chireix Power Combiner

Étude systémique pour l'alimentation hybride

Efficient Computation of Sensitivity Coefficients of Node Voltages and Line Currents in Unbalanced Radial Electrical Distribution Networks

Open-loop control of a separated boundary layer

Forced reattachment in separated flows: a variational approach to recirculation length reduction

Study of optimal design of polygeneration systems in optimal control strategies

Boundary layer effects on the vortex shedding in a Donaldson-type hydrofoil

Open-loop control of a separated boundary layer

A linearized approach for the control of aerodynamic forces in flow past a square cylinder

Étude systémique pour l'alimentation hybride

Forced reattachment in separated flows: a variational approach to recirculation length reduction

A 10-W modified LINC Power amplifier with a reduced-size Chireix Power Combiner

Obstacle-induced spiral vortex breakdown

Efficient Computation of Sensitivity Coefficients of Node Voltages and Line Currents in Unbalanced Radial Electrical Distribution Networks

Study of optimal design of polygeneration systems in optimal control strategies

Open-loop control of a separated boundary layer